Twenty years ago, visiting a primary school to which we were thinking of sending our first daughter, my wife and I were amazed to discover that full-fat milk was banned from its kitchens: the children were to be offered only skimmed or semi-skimmed.

Yet the amazement was even greater on the part of the woman showing us around, when we told her it was odd that the milk provided to the pupils was only in varieties with one of the most nutritious components excluded. She exclaimed that they were acting according to the best medical advice, which all the other parents accepted.

The second part of her statement we were in no position to dispute. And she was right that the medical establishment argued that even little children should be steered away from animal fat and cream. It had been saying this since the late 1960s, when the orthodoxy emerged that the most essential element in a healthy diet was food low in fat. It’s easy to see why this should have been so easy to propagate. The same word — fat — is used to describe both physical grossness and the type of food we were to forswear: “Don’t eat fat and you won’t get fat.”

Fat tastes good because it is good for us — that is evolution at work

There have been two problems with this. The first is that being fat is not in itself unhealthy. Increased risk of premature mortality is not correlated with being overweight; it is more associated with being underweight.

The morbidly obese are indeed at high risk — hence the term “morbidly” — but such extreme levels of obesity are not usually associated with people who drink too much full-fat milk, or eat too much brie, or guzzle gargantuan steaks. No, these tend to be people whose diet is full of sugar.

In 1972 a British professor of nutrition, John Yudkin, wrote a book — Pure, White and Deadly — which challenged the notion that saturated fat was the dietary demon. He asserted that excessive sugar intake was the more likely cause of such contemporary ailments as diabetes, heart disease and extreme obesity. He was ostracised by the nutritionary and medical establishment, and even portrayed as being in league with the meat and dairy industry (which he wasn’t).

The problem Yudkin identified was that if we don’t get our energy from animal fats and protein, then carbohydrates would fill the calorie gap: and that is a recipe for a high sugar intake. Not only that, but low-fat foods advertised as complying with the official medical recommendations and the dictates of fashion would be almost tasteless — and therefore could hardly be sold to the masses unless supplemented with prodigious quantities of sugar (breakfast cereals being the most obvious example).

The fact that naturally occurring fat tastes wonderful is neither a matter of opinion nor accidental. It tastes good because it is good for us — that is evolution at work. Saturated fats, for example, are present in milk from the mother’s breast. By contrast, the first production of refined sugar, which contains nothing of nutritional value, dates from the 16th century: countless millennia after natural selection had perfected the human digestive system.

Anyway, here we are anno domini 2016 and the battle lost by the late Professor Yudkin has been rejoined by a body called the National Obesity Forum. Last week, along with a group of doctors under the equally unlovely name of the Public Health Collaboration, it published a report declaring that the longstanding official advice promoting low-fat foods had been “perhaps the biggest mistake in modern medical history, resulting in devastating consequences for public health”. The report went on to argue: “Eating fat does not make you fat . . . The most natural and nutritious foods available — meat, fish, eggs, dairy products . . . all contain saturated fat.”

A founding member of the Public Health Collaboration, Dr Aseem Malhotra, a consultant cardiologist, added that the current advice from Public Health England, promoting low-fat foods, “is more like a metabolic timebomb than a dietary pattern conducive to good health”. His colleague Professor Iain Broom of Robert Gordon University declared: “Our populations have for almost 40 years been subjected to an uncontrolled global experiment that has gone drastically wrong.”

The report even accused the medical establishment of having been “corrupted by commercial influences”, as the recent NHS guidelines had been drawn up in association with the food and drink industry. My advice to Dr Malhotra and his colleagues is to refrain from this argument by insinuation. It wasn’t attractive when used against Professor Yudkin by those advocating a low-fat diet and is no more so when deployed by the other side.

But people are understandably angry. Not least Dr Michael Mosley, author of the 5:2 diet, who wrote how under the influence of established medical opinion he had persuaded his father — a sufferer from type 2 diabetes — to go on a low-fat diet. “Following my advice he put aside the fats, ate more starchy foods — and got fatter and fatter. His diabetes got steadily worse . . . he died of heart failure. If I had known what I know now about the high failure rate of low-fat diets, my advice would have been completely different and he might have lived to see his grandchildren grow up.”

I confess to a certain smugness, as someone long devoted to a diet high in protein and dairy products. This has not been through conscientious regard for my own health, but pure hedonism. And there are problems associated with such an eating style. A few years ago I suffered the excruciating agonies of kidney stones, and was told they were of the type caused by excessive protein and dairy consumption.

The overriding truth, predictably, is that any diet over-reliant on a particular foodstuff can have unfortunate consequences. The Atkins high-protein diet is a sure-fire way to lose weight, but the price to pay is foul breath — and epic constipation. (As one Atkins devotee once told me: “I had to knock it off with a stick.”)

Yet this particular unbalanced diet seems preferable to the faddism practised especially by younger women — known as “clean eating”. As Katie Glass’s article on the phenomenon in today’s Sunday Times Magazine reveals, this has led to a dramatic increase in veganism — which now has more than half a million devotees in this country, mostly young urban females. This is not a healthy diet — if it were, its advocates would not need to spend so much of their income on vitamin supplements at Holland & Barrett in order to remain upright.

Who knows — perhaps their minds were distorted long ago at primary school, when they were told that full-fat milk was “bad”. By the way, the government’s “free school milk requirements”, which came into force only last year, demand that “you may only offer lower-fat milk (not more than 1.8% fat content, such as semi-skimmed, skimmed or 1% fat milk)”. This, the nation’s school canteens are told, “reflects current Department for Education advice”.

Eighty years ago, JM Keynes wrote: “Practical men, who believe themselves to be quite exempt from any intellectual influence, are usually the slaves of some defunct economist.” He went on to name “civil servants and politicians” as the worst example of this.

Today the departments of health and education are the slaves of defunct nutritionists.

Candice Springfield

In addition to being a happy mother of 3 wonderful kids, I’m a writer and a nature lover. I created this goal to share my lover for nature and particularly the UK coastline with others. I really hope my stories and photos will help you see the magic of the world we all live in.